This new full color book reports on the mail carried by Butterfield's Overland Mail between September 1858 and March 1861 on the Southern Ox Bow Route, and beginning in July of 1861 on the Central Route. Also, to include additional information and artifacts from US transcontinental mail carried immediately before and immediately after the existence of Butterfield's Overland Mail Co.In most instances within his previous three books on Butterfield's Overland Mail Co., he focused primarily on the Arkansas route. This volume, by contrast, expands to focus on the entire route of the Butterfield. Also, by contrast, this volume focuses on Butterfield's presence on the Southern Ox-bow Route and later on the northern Central Route. In addition, this volume covers the entire time period of the Overland Mail Company's contract with the postal system: 1858-1864.While the purpose of this research of the Overland Mail was to satisfy his personal curiosity, he is hopeful that summary of Butterfield Postal History will also make a contribution to Butterfield's Overland Mail Co. new status as a National Historic Trail.